Ironworker Joseph Voll tightens rebar during construction of the 1,100-foot-tall Wilshire Grand tower. It will be the tallest structure west of Chicago, its developers say.

Ironworker Joseph Voll tightens rebar during construction of the 1,100-foot-tall Wilshire Grand tower. It will be the tallest structure west of Chicago, its developers say. (Mel Melcon / Los Angeles Times)

Beneath its design is the engineering of what is arguably the most complicated high-rise to be built in the United States. Calculated to sway during powerful Santa Anas and absorb ground movement during the most severe earthquakes, it is wedded aesthetically and technically to the unique...Mel Melcon / Los Angeles Times